Machine for salvaging carbons



Feb. 4, 1936. w. E. cRoss MACHINE FOR SALVAGING CARBONS Filed Jan. 21,1935 m T N E V m WALLACE E.CROSS ATT NEY Patented Feb. 4, 1936 stir 5Claims.

This invention relates to apparatus for salvaging the carbon electrodesof arc lights, and particularly of picture projectors.

In operating the larger types of picture projectors, it has heretoforebeen the practice to discard the positive carbon electrodes when burneddown to about one-third of their original length, because this is theapproximate distance between the arc and a certain feed mechanism bywhich 7 the electrodes are fed, both forwardly and rtatively. Sincethese electrodes cost between 40 and 50 apiece, it is apparent that theaforementioned practice involves quite an expensive waste.

An object of the invention is to provide a highly simplified machine orapparatus for turning a shoulder on the rear (or hard) end of a carbonelectrode for such engagement by a tubular adapter as will permit thelatter to maintain a flush relation with the main body of the electrode.

A further object is to so enclose the cutter of such a machine and to soseal the electrode engaging said cutter as to very positively preventany escape from the machine of carbon particles and resultant detractionfrom the cleanliness of the p. when room in which the machine wouldordinarily be employed.

These and various other objects the invention attains by theconstruction hereinafter described, and illustrated the accompanyingdrawing, wherein:

Fig. 1 is a view of the machine in axial vertical section.

Fig. 2 is a fragmentary vertical cross section of the machine, takenupon the line 2-2 of Fig. l and primarily showing an electrode-holdingchuck.

Fig. 3 is another fragmentary vertical cross section, taken upon theline 33 of Fig. 1, and particularly showing the cutter.

Fig. l is a fragmentary section repeating a portion of Fig. 1, butshowing the initial position of the cutter.

Fig. 5 is a perspective view of an electrode equipped with the adaptermade applicable to the housing. Adjacent to the bearing i there ismounted fast on said shaft a crank wheel 3 provided with the operatinghandle 9. In being rotated by the crank wheel, said shaft is adapted tobe also slid into the housing from its position shown 5 to thatappearing in Fig. l, for the purpose of feeding the cutter to the work.This feeding movement is limited by forming the shaft with an annularslot E9, and engaging in said slot a screw M or other stop element ca; dby the bearing 1.

In axially opposed relation to the shaft 8, the portion of the housingis formed with an opening threaded to. receive an electrode-holdingchuck. As illustrated, this chuck comprises a sleeve 52 having its innerend it enlarged and screwed into opening, and a collet M in said sleevefor ounting the electrode i and accurately axially aligning it with thecutter. The collet is formed with a plurality of slits i5 extendinglongitudinally of and radially to the collet from its inner end for amajor portion of its length, thus forming a number of flexible tonguesit which may be contracted to grip the electrode. The inner of thecollet is exteriorly sonically flared, as indicated at ii, to fit in acorrespondingly flared terminal enlargement of the opening of the sleevei2, so that by increasin ly drawing the flared end portion of the colletinto the sleeve, the tongues it are contracted to firmly clamp anelectrode. Adjacent to the outer end of the sleeve it, a nut i8 isthreaded upon the corresponding end of the collet to provide for forcingthe latter outwardly in the sleeve, to thereby effect inward flexing ofthe tongues i6, and said nut is preferably equipped with one or moreradial operating handles I9. Rotation of the collet relative to thesleeve is prohibited by mounting in the sleeve a pin 2% or the likeengaging in a key-way 2| formed in the collet.

In use of the described machine, the shaft 5, with its crank wheel 8, isinitially outwardly shifted to the limit established by the stop screwII, as shown in Fig. 5. The hard or unburned end portion of a carbonelectrode is then insorted in the collet M until it engages the cutter3. The nut i8 is then turned to cause a firm gripping of the electrodeby the chuck. The shaft 6 is now rotated and is at the same timesubjected to a slight axial pressure such as to feed the cutter againstthe electrode. Upon formation by the cutter of the desired reducedportion 5 of the electrode, further advance of the cutter is prohibitedthrough bottoming of its interior opening against the electrode, as Fig.l indicates.

The described machine may be easily adapted to operate upon electrodesof different thicknesses by providing several different sized chucks foralternative engagement with the housing 2.

To an electrode machined as described, there may be applied a tubularadapter 22 equal in exterior diameter to the electrode and interiorlyadapted to fit snugly on the reduced end portion 5, such adapterpreferably having one or both ends slit longitudinally as indicated at23, to permit a slight resilient expansion of the adapter by theelectrode to render the connection more firm. The increased length ofthe electrode imparted by the described adapter permits consumption ofthe electrode to a considerably greater extent than has heretofore beenfeasible, and consequently very materially reduces that portion of theelectrode Which must be eventually discarded.

It is a vital feature of the described invention that the adapter isapplied to the unburned or hard end of the electrode, since this permitsof the exact axial alignment of the electrode and adapter that isessential to practical use of the latter. The burned end of theelectrode is ordinarily gradually tapered, due to exposure to the arc,and has lost its original regularity to an extent prohibiting accuratemachining. Application of an adapter to the unburned end is further tobe preferred, for the reason that this leaves the opposite end incondition for immediate efficient use, whereas a reversal end for end ofthe electrode for salvaging purposes would present to the arc an endrequiring exposure thereto for at least several minutes before the arccould acquire a normal and steady brilliancy.

The invention is presented as including all such modifications andchanges as come within the scope of the following claims.

What I claim is:

l. A machine for salvaging carbon electrodes comprising a support, ashaft rotatable and longitudinally slidable on said support, a commonmeans for rotating and sliding said shaft, an annular cutting toolterminally mounted on said shaft, a sleeve coaxial with said shaftdetachably mounted on said support in spaced relation to the cuttingtool, a collet mounted in said sleeve and longitudinally slit to formwith the sleeve a chuck adapted to clamp a carbon electrode in coaxialrelation with said cutting tool, means carried by said sleeve resistingrotation of said collet, means for effecting contraction of the collet,and means for limiting sliding actuation of said shaft.

2. A machine for salvaging carbon electrodes comprising a housing havinga reduced upper portion, a shaft journaled and longitudinally slidablein a Wall of said reduced portion, an annular cutter terminally mountedon said shaft within the housing, a common means for rotating andsliding said shaft, a chuck mounted in an opposed wall of said housingcoaxially with said shaft and mounted to clamp the carbon electrode inposition for engagement by said cutter.

3. A machine for salvaging electrodes comprising a support forming acutting chamber, a cutting tool within said chamber, a shaft carryingsaid tool, rotatable and longitudinally movable in a wall of saidchamber, an electrode-holdin chuck mounted coaxially with the shaft inan opposite wall of said chamber, and a common means, exterior to saidchamber for rotating the shaft and actuating it longitudinally.

4. A machine for salvaging carbon electrodes comprising a support, anannularly grooved shaft rotatable and longitudinally slidable on saidsupport, a common means for rotating and sliding the shaft, an annularcutting tool terminally mounted on the shaft, a chuck mounted on thesupport in spaced relation and in axial alignment with the cutting tooland having a central axial opening for receiving a carbonelectrodeengaged by the chuck, and a stop element carried by the support andengaging in the annular groove of the shaft to limit sliding actuationof the shaft.

5. A machine for salvaging carbon electrodes comprising a support, ashaft rotatable and longitudinally slidable on said support, a commonmeans for rotating and sliding the shaft, an annular cutting toolterminally mounted on said shaft, a chuck mounted on the support inspaced relation and in axial alingment with said cutting tool, saidchuck having a central axial opening for receiving a carbon electrodeengaged by the chuck, and means upon the support for limiting slidingactuation of said shaft, said support forming a housing to receivecuttings, and the shaft and chuck being mounted in opposed walls of saidhousing.

WALLACE E. CROSS.

